Automatic control of clutch and throttle actuation of an automotive vehicle



Sept 24, 1940. R 's wHlTTlNGToN AUTOMATIC CONTRL 0F CLUTCH AND THROTTLE`ACTUATION oF AN AUTOMOTIVE VEHICLE Original Filed July l5, 1952 dmFLWJW////////////////ff INVENTOR WMP/A52 Wwf/74570 ATTORN atented Sept. 24,1940 THROTTLE ACTUATI TIVE VEHICLE N 0F AN AUTOMO- Ralph S. Whittington,Springfield, Mass., assign.- or to Bendix Products Corporation, SouthBend, Ind., a corporation of Indiana Original application July 15, 1932,Serial No. 622,703. Divided and this application November 1, 1937,Serial No. 172,172.

This invention relates to an automatic control means for use incontrolling the actuation or' throttle and clutch of anautomotivevehicle in their proper relation.

t One ci the primary objects of this invention is to provide a controlmeans oi the above-n mentioned character which will effect a slowercontacting oi the clutch plates after the vehicle has been free wheelingor coasting for a time,

lll than is obtained when the gears of the trans... mission are beingnormally shifted and the ac celerator depressed to drive the vehicle.

@ther objects oi the invention and desirable details of construction andcombinations oi M parts will become apparent from the followingdescription oi' a preferred embodiment, which description is taken inconjunction with the ac companying drawing, in which:

Figure i is a semi-diagrammatic view partly in m section of a controlmeans constructed in accordance with this invention;

Figure 2 is a fragmentary cross-sectional view talren substantially onthe line t-Z of Figure 1;

Figure 3 is a fragmentary cross-sectional view pg' taken substantiallyon lthe line 3 3 of Figure l;

Figure i is a semi-diagrammatic view partly in section oi' the actuatingdiaphragm, as shownA in Figure l, with a control valve for thisdiaphragm, this mechanism constituting the essence m oi my invention;and

Figure 5 is a fragmentary sectional view taken substantially on the line5--5 of Figure t.

in general, this invention provides an automatic control means for theclutch of an autom motive vehicle which also accelerates the motorautomatically at the instant that the clutch be gins to engage. In priordevices of this nature this has been accomplished by means of mechanicalconnection to the accelerator pedal oi' such hind that the carburetorthrottle valve would be opened the proper amount at the time the clutchstarted engagement. However, this has been a delicate adjustment and onethat required frequent adjustment to secure the proper motor is stillrevolving at several hundred revolutions per minute, and after the gearshave been shifted and the accelerator depressed again, the motor willpick up speed very rapidly. But after the car has been coasting for atime, the motor has had time to slow down to a low speed and is idling.Then when the accelerator is depressed again to drive the car, the motorspeed,

must necessarily require more time to come up to the speed of the carthan in the former case where the motor is already turning rapidly. Theresult is that after free wheeling, the clutch will engage before themotor cornes up to the speed oi the car, and a jerlr is felt as themotor is brought up to speed. This invention provides means of delayingclutch engagement until the motor comes up to speed, after. the car hasbeen free wheeling, without slowing up the clutch. engagement during theshifting of the gears.

lllfhis invention also provides a method of contacting the clutch platesunder full control of the accelerator pedal position, giving theoperator of the vehicle better control while maneuvering the car inclose quarters.

Referring then `to the drawing wherein like reference charactersdesignate corresponding parts through all views, there is shown inFigure l a. system composed of a conduit II adapted to be connected byconduit to the intake manifold of the motor of an automotive vehicle.Conduit i is provided with lateral extensions 2 and 3, which slidablyreceive piston t and valve 5. Piston il is connected by linkage t toaccelerator pedal l. The conduit i is divided into passages t, t, and itby piston il and valve 5. Piston 4 operates in bore il to control thecommunication of passages 8 and t. Valve 5 operates in bore i2 tocontrol communication between passages 9 and IIl. Passage i3 is providedto place passage t in communication with passage I0 only at such timesthat the reduced portion I4 of piston 4 is in alignment with passage 8,as shown in Figure l, which corresponds to the position of completerelease of the accelerator. Piston 4 is also provided with groove itadapted to place passage ll in communication with the atmosphere upon apredetermined movement of piston 4. Valve 5 is actuated by spring I6 andis held in bore I2 by plug I1. Hole i8 opens bore I2 to the atmosphere.Conduit i terminates in diaphragm casing I9, placing one side ofdiaphragm 20 in communication with passage Ill. Diaphragm 20 is exposedon its other face to atmospheric pressure through port 2| and isconnected to the clutch plate 22 by stem 24. Clutch plate 22 is moved tocontact clutch plate 23 by clutch springs 25. Tapped into the passage I0is the conduit 26, which at its other end is tapped into the carburetorriser 21 at the rectangular port 28. Carburetor riser 21 is divided intopasage 29 and passage 38 bycarburetor throttle valve 3|.'

Passage 29 is adapted to be connected to the intake manifold of themotor of the vehicle, and passage 30 is adapted to be connected to thecarburetor. Carburetor throttle valve 3| is actuated by arm 32 which islinked to the accelerator by rod 33 and piston 4. Rod 33 is providedwith the enlarged portion 34 which contains the bore 35 in which thepiston 36 is slidably mounted. Piston'36 is formed from an extension ofpiston 4 and is held in bore 35 by ring 31 pressed into bore 35. Piston36 is provided with thesmall holey 38 to open bore 35 to atmosphere.Spring 39 is provided to actuate the throttle Valve in opposition to theaccelerator pedal. Carburetor riser 2'I also contains the bore 48, whichslidably receives piston 4I provided with taper 42 which is contacted byring 43 pressed into bore 48 to form a stop for piston 4 I. Port 44exposes piston 4| to atmospheric pressure. Passage 45 containing theadjustable restriction 48 places passage 30 in communication with bore4|] and port 41 communicates between bore 40 and passage 29. Spring 48actuated piston 4| and plug 49 closes bore 40. K

In the operation of the system, passage 8 is subject to the vacuum inthe intake manifold and all parts are shown in Figure 1 in the positionthey occupy while the motor idles. Vacuum from passage 8 rst actsthrough passage I3, groove 58 of valve 5 allowing atmospheric pressureacting through hole I8 to overcome spring I6 and place valve 5 in thepositin shown in Figure l. Then by virtue of the reduced portion 5I ofvalve 5, diaphragm 20 is placed in direct communication with passage 8,allowing atmospheric pressure acting through port 2| on diaphragm 20 toovercome clutch springs 25 and move the clutch plates to the positionshown in Figure 1. The gears of the transmission may now be shifted.When the accelerator pedal 1 is depressed, piston 4 is moved in thedirection of the arrow to cut off vacuum in passage 8 from passage 9 andpassage I3, and at approximately the same time place passage 8 incommunication with the atmosphere through groove I5 in piston 4. As airis admitted to passage 9, it passes valve 5 by virtue of the reducedportion 5| and enters diaphragm casing I9 to begin to equalizeatmospheric pressure acting on diaphragm 20, but by virtue of clutchsprings 25 pulling on diaphragm 20 a vacuum suflicient to overcomespring I6 acting to close valve 5 is developed in passage I8 as theclutch plates move toward engagement.

As soon, however,- as the clutch plates begin to contact, the pull ofthe clutch springs on diaphragm 28 will decrease,.causing a drop invacuum in passage I0. This drop in vacuum will be communicated to theexposed area of valve 5, and, spring I6 is of such strength that Valve 5is moved to close passage 9 from passage vII) at some predeterxminedclutch plate pressure, and further engagement of the clutch must beeiected by by atmosphere entering passage I0 through port 28 and conduit26.

The operation described above takes place When the accelerator pedal 'Iis depressed just enough to move piston 4 to shut off vacuum in passage8, and open passage 9 to the atmosphere through groove |5 in piston 4..While the accelerator pedal is in this position, the throttle valve 3|has moved only slightly and port 28 is still exposed largely to Vacuumin passage 28. Hence vacuum will still exist in conduit 28. This vacuumwill be transferred to conduit I0 and the clutch actuating member 20.However, regardless of the degree of vacuum at port 28, the vacuum atpassage I0 cannot, while piston 4 opens passage 9 to atmosphere, exceedthe vacuum at which valve "5 will allow atmospheric pressure actingthrough hole I8 to overcome spring I6, and thus admit more atmospherefrom passage 9. Thus valve 5 at this stagey acts as a vacuum regulatingvalve and insures thaty the clutch will remain partially engaged as longas atmospheric pressure exists in passage 9.

Passage I0 communicates with the carburetor riser through conduit 26 andport 28 which is rectangular in shape but narrow enough to have theproper restriction of its capacity. Port 28 is arranged so that all ofits area is exposed to vacuum in passage 29, when the accelerator pedal1 is ,completely released and the throttle valve is in the positionshown in Figure l. However, as the throttle valve is opened, more of thearea of port 28 is exposed to near atmospheric pressure in passage 30.'Ihe result is that as valve 3| is opened its edge passes over the faceof port 28, producing a continuous drop in vacuum in the conduit 26, andthis action results in atmosphere being admitted to passage I0 anddiaphragm 20 from passage 38 as the above action takes place. Thus thepressure in passage l0 depends on the proportionate amount of the areaof port 28 that is exposed to the vacuum in passage 29 and nearatmospheric pressure in passage 30, and the vacuum acting on diaphragm20, and consequently the clutch plate pressure, can be increased ordecreased accordingly as valve 3| is opened or closed. Complete clutchengagement will be obtained when port 28 is completely exposed to nearatmospheric pressure in passage 30.

When the accelerator pedal 1 is depressed slowly, as when starting thevehicle, air passes through hole 38 from bore 35 fast enough to preventthe compression of spring 39 and the motion of valve 3| until piston 36reaches the bottom of bore 35. At approximately the same time, piston 4begins admitting atmosphere to diaphragm 20. The result is that themotor begins to accelerate as the clutch begins to engage. But when theaccelerator pedal 1 is depressed rapidly, as after free wheeling, air iscompressed in bore 35 due to the limited capacity of hole 38, and spring39 is 5 compressed resulting in the opening of valve 3| more in advanceof clutch engagement. Obviously, the clearance of piston 36 in bore 35could be made of the proper value to accomplish the same result. f

During the normal idling of the motor, the vacuum in passage 29- actingthrough port 41 on piston 4| overcomes spring 48 and holds piston 4Iagainst stop 43, as shown in Figure 1, due to atmospheric pressureacting through port 44. But at the instant that the clutch plates beginto contact, there is a drop in vacuum in the intake system of the motorand in passage 29. 'Ihe drop in vacuum referred to occurs as the clutchbegins to engage because at this time the motor begins to developtorque. As the motor is loaded more, the vacuum in the intake systemwill decrease, and can be made to decrease to a negligible quantity, aswhen the throttle Valve is open wide at low'motor speeds. This drop invacuum u hill begins to equalize atmospheric pressure on piston il, andallows spring 48 to move piston 4I to uncover passage 45 and admitmixture from passage 30, through passage 45 to bore 40, and` throughport 41 to the intake system of the motor. Piston 4I is provided withtaper 42 so that the greater the drop in vacuum in the intake systernduring the contacting of the clutch plates, the greater the rate atwhich mixture is admitted to the intake system to accelerate the motor.Thus a means of accelerating the motor automatically as the clutchbegins to engage is provided. and the amount that the motor isaccelerated increases as the speed of clutch engagement increases, sincethe vacuum will drop more in the intake system during the contacting ofthe clutch plates, the greater the rate at which mixtureis admitted tothe intake system to accelerate the motor. Thus a means of acceleratingthe motor automatically as the clutch begins to engage is provided, andthe amount that the motor is ac celerated increases as the speed of`clutch engage ment increases, since the vacuum will drop more in theintake system of the motor when the clutch is engaged more rapidly.

lin Figure i is illustrated a diaphragm controlled clutch with a specialvalve for the diaphragm to be used in a control system of the natureillustrated in Figure 1. Vacuum in passage 52 acts through slot El ofvalve 60 as long as slot 8l is in register with the interior ofdiaphragm casing it. However, as soon as slot E I completely enterspassage 52, air can be removed from the interior oi diaphragm casing I9to effect further motion oi clutch plate 22 only through groove 62 ofvalve tt. Thus vacuum in passage 52 can act to rapidly disengage clutchplates 22 and 23, but after they have been disengaged some distance,their further motion apart is made much slower by the closing oi thepassage through the slot 5I. Adjustable restriction 63 in groove 62makes possible an adjustment of the speed at which theclutch platescontinue to move apart after slot 6I completely enters passage 52. Whenvacuum is re- ,v leasediin passage 52 and atmosphere is allowed to enterit to effect an engagement of the clutch, one-way check valve 64 opensdue to the fact that pressure in passage 52 is greaterthan in thediaphragm casing I9 and provides an additional path ior air to How frompassage 52 to casing I9 to effect a clutch engagement. Port 65 isprovided to govern the capacity of this path. Thus, after slot 62 hascompletely entered passage 52, a path oi two capacities is providedbetween passage t2 and the interior of diaphragm casing I9, the pathhaving a greater capacity when motion of air is toward diaphragm casingI9, but being controllable in capacity in both directions.' The resultis that while the gears of the transmission are being normally shifted,the clutch will be disengaged only approximately to the point where alloi slot 62 enters passage 52, because the interval of time that theaccelerator is released is small, andLcnsequently vacuum will not bepresent inpassage 52 for any length of time. .This is desirable since aquick engagement of the clutch is desired at this time, because themotor is turning fast when the accelerator is depressed and it will comeup to speed comparatively fast. But

when the car has been free wheeling for a time and the motor speed hasreduced to idling, vacuum has been present in passage 52 for some time,and the action of this vacuum through groove G2 will have moved theclutch plates to the maximum distance apart. Then when the motor isaccelerated to drive the car again, the contacting of the clutch plateswill be delayed the proper amount by the combined capacity of the paththrough groove 62 and one-way check valve B4, which path must be theproper capacity to delay the contacting oi the clutch plates until themotor, which has been idling and will come up to speed slower, has hadtime to come up to the proper speed. Thus a means is provided that takescare of the different conditions existing while shifting the gears ofthe transmission and while starting to drive the car again after lt hasbeen free wheeling or coasting.

The object in retarding the motion of the clutch plate 22 towardreleased position during the latter part of `this motion, is to providea means of delaying the next engagement of the clutch in proportion tothe time that the motor has been idling. This is desirable, since thelonger the motor has been idling the slower it will be running, andhence the longer it will take to come up to speed again when theaccelerator is depressed again. Due to the check valve 64 and the port65, the clutch engagement will always be delayed in proportion to theamount o! air that must pass through port 52 to eiect a clutchengagement, and this quantity of air will increase as the position oi'the clutch plate 22 changes to the left in Figure 4, this position beingconsidered as the starting point for clutch engagement as theaccelerator pedal is depressed to start a clutch engagement.

The invention heretofore described is disclosed in my Patent No.2,103,284, granted December 28, 1937, this application constituting adivision thereof.

While one illustrative embodiment has been described, it is not myintention to limit the scope oi. the invention to that particularembodiment, or otherwise than by the terms of the appended` claims. i

I claim:

l. In an automatic control means for the clutch of an automotivevehicle, the combination with the intake system and a mechanism forcontrolling the acceleration of the motor, of a member responsive tovacuum in said intake system for releasing the clutch, means providing apassage between said intake system and said pressure responsive member,means to open said passage whereby vacuum from said intake systemactuates said pressure responsive member to release said clutch, meansoperating upon the actuation oi' said mechanism to reduce the vacuumacting on said pressure responsive member whereby said clptch is movedtoward engaged position, means operating after said clutch has beenreleased to slow up further motion toward release of said clutch.

2. In an automatic control for the clutch of an automotive vehicle, thecombination with the intake system and a mechanism for controlling theacceleration of the motor, of a pressure responsive means for releasingthe clutch, means providing a passage between said intake system andsaid pressure responsive means, means operating, when the aforementionedmechanism is released, to openrsaid passage whereby vacuum from saidintake system actuates the pressure responsive means to release theclutch, means operating upon the actuation of said mechanism to reducethe vacuum acting on said pressure responsive means whereby said clutchis moved toward engaged position, means operating after said clutch hasbeen released to slow up further motion toward release of said clutch,means operating after the actuation of said acceleration controlmechanism causes a reduction of vacuum acting on said pressureresponsive means, to slow up the motion of said clutch towardengagement.

3. In an automatic control for the clutch of an automotive vehicle, thecombination with the in- -take system and a mechanism for controllingthe acceleration of the motor, of a pressure responsive means forreleasing the clutch, means providing a passage between said intakesystem and said pressure responsive means, means operating when themotor is idling to open said passage whereby vacuum from said intakesystem actuates said pressure responsive means to release the clutch,means operating upon the actuation of said acceleration controlmechanism to reduce the vacuum acting on said pressure responsive meanswhereby said clutch is moved toward engaged position, means operatingafter said clutch has been released to slow up further motion of saidclutch toward release, means operating, after the actuating of saidacceleration control mechanism causes a reduction of vacuum acting onsaid pressure responsive means, to slow up the motion toward engagementof said clutch through a portion of its motion toward engagement.

4. In an automatic control means for the clutch of an automotivevehicle, the combination with the intake system and a mechanism forcontrolling the acceleration of the motor, of a pressure responsivemeans for releasing the clutch, means providing a passage between saidintake system and said pressure responsive means, means operating, whenthe aforementioned mechanism is released, to open said passage wherebyvacuum from said intake system actuates said pressure responsive meansto release said clutch, means operating upon the actuation of saidmechanism to reduce the vacuum acting on said pressure responsive meanswhereby said clutch is moved toward engaged position, and a valveactuated upon the motion of said clutch, said valve affecting thecapacity of communication between said intake system and said pressureresponsive means.

5. In an automatic control means for the clutch of an automotivevehicle, the combination with the intake system and a mechanism forcontrolling the acceleration of the motor, of a pressure responsivemeans for releasing the clutch, means providing a passage between theintake system and said pressure responsive means, means operating toopen said passage whereby vacuum from said intake system actuates saidpressure responsive means to release said clutch, means operating uponthe actuation of said mechanism to reduce the vacuum acting upon saidpressure responsive means whereby said clutch is moved toward engagedposition, and a valve actuated upon the motion of said clutch, saidvalve decreasing the capacity of said passage from said intake system tosaid pressure responsive means after said clutch has moved a certaindistance toward released position, said valve also providing anadditional passage in one direction only, between said passage and saidpressure responsive means, said additional passage acting to permit themotion of said clutch toward engagement during the period that saidvalve aiects communication between said passage and said pressureresponsive means.

6. In an automatic control means for the clutch of an automotivevehicle, the combination with the intake system and a mechanism forcontrolling the acceleration of the motor, of a pressure responsivemeans for releasing the clutch, means providing a passage between saidintake system and said pressure responsive means, means operating whenthe motor is idling to open said passage whereby vacuum from said intakesystem actuates said pressure responsive means to release said clutch,means operating on the actuation of said acceleration control mechanismto reduce vacuum acting on said pressure responsive means whereby saidclutch is moved toward engaged position, and a valve actuated upon themotion of said clutch, said valve reducing the capacity of communicationbetween said passage and said pressure responsive means after saidclutch has moved to disengage, means providing a one way check valvepermitting flow of atmosphere from said passage to said pressureresponsive means when pressure in said passage is greater than in saidpressure responsive means.

RALPH S. WHI'I'TINGTON.

